DE102017121865A1 - Method for monitoring the load of a chassis component when driving with a motor vehicle and motor vehicle - Google Patents

Abstract

The invention relates to a method for monitoring the load of a chassis component when driving with a motor vehicle having at least one roll stabilizer with a roll stabilizer sensor, wherein the roll stabilizer sensor, a torque is measured directly or indirectly, which is a stabilizer element of the roll stabilizer Torsion claimed, and based on the measured torque, a component load indication is determined. Furthermore, the invention relates to a motor vehicle having at least one roll stabilizer, which has a roll stabilizer sensor, wherein by means of the roll stabilizer sensor, a torque is directly or indirectly measurable, which claims a stabilizer element of the roll stabilizer to torsion, and with an evaluation, which is set up to determine a component load specification based on the measured torque

Description

The invention relates to a method for monitoring the load of a chassis component when driving with a motor vehicle. Another object of the invention is a motor vehicle.

In the prior art, methods are known with which road quality data can be derived when driving with a motor vehicle. Such a method describes, for example, the US 9 108 640 B2 , In this method, the position of the motor vehicle and vibrations are determined in the vertical direction and derived from it position-dependent road quality information. The road quality data obtained in this way are suitable for improving road maps for navigation applications. With the known method, defects in the sensors used can be detected on the basis of the road quality data, but it is not possible to monitor loads on individual components.

Against this background, the task is to enable the monitoring of the load of chassis components of a motor vehicle while driving.

The object is achieved by a method for monitoring the load of a chassis component when driving with a motor vehicle having at least one roll stabilizer with a roll stabilizer sensor, wherein the roll stabilizer sensor, a torque is measured directly or indirectly, which is a stabilizer element of the Wankstabilisators claimed to torsion, and based on the measured torque, a component load indication is determined.

In the method according to the invention, a torsional moment is measured with the roll stabilizer sensor of the roll stabilizer, that is to say a torque which stresses a stabilizer element, in particular a torsion spring, of the roll stabilizer for torsion. The measurement can be done directly, i. directly detect the torque. Alternatively, the measurement may be indirect, for example by directly measuring a path from which the torque is derived. Based on the measured torque then a load specification is determined for a component. The torque measured by the roll stabilizer sensor is usually used to control an actuator of the roll stabilizer, so that the roll stabilizer sensor has a double function for reducing rolling movements and for determining the component load indication.

Preferably, the roll stabilizer is an active roll stabilizer, in particular an electromechanical roll stabilizer, over which roll motions of the motor vehicle can be reduced. Such unwanted rolling movements can occur when driving through curves or driving over bumps. The roll stabilizer can counteract such roll behavior. Preferably, the roll stabilizer is arranged on an axle of the motor vehicle. Particularly preferably, the roll stabilizer comprises an actuator for generating a torsional or torsional moment, in particular an electric motor. In the method, a motor vehicle is preferably used, which has several, in particular two, roll stabilizers, for example a first roll stabilizer on a front axle of the motor vehicle and a second roll stabilizer on a rear axle of the motor vehicle.

To record the component load specification, the torque can be measured continuously. Alternatively or additionally, it is possible to measure the torque for detecting the component load indication event-controlled, in particular when the torque exceeds a predetermined threshold. For example, a measurement of the torque can take place whenever an actuator of the roll stabilizer is active, e.g. to counteract unwanted rolling motion.

Preferably, the motor vehicle on several roll stabilizers, each with a roll stabilizer sensor, wherein the roll stabilizer sensors of the roll stabilizers each torque is measured, based on the measured torques component load information for several components, such as stabilizer elements of the plurality of roll stabilizers are determined. For example, the motor vehicle may have exactly two roll stabilizers.

According to an advantageous embodiment, the component load specification comprises an indication of the load of the stabilizer element of the roll stabilizer, for example an average applied torque, a minimum torque, a maximum torque, a torque range, a time profile of the torque or a total damage of the stabilizer element.

According to an advantageous embodiment, the component load indication comprises an indication of a load of a component connected to the roll stabilizer, in particular a coupling rod. The component load specification can be an average applied tensile force, a minimum tensile force, a maximum tensile force, a tensile force span, a temporal course of the tensile force or a total damage of the component connected to the roll stabilizer, in particular the coupling rod. be. The tensile force applied to the component connected to the roll stabilizer can be determined on the basis of the measured torque and a predetermined lever arm.

According to an advantageous embodiment, the motor vehicle has a position-determining device, wherein the position of the motor vehicle during the measurement of the torque is determined and the determined component load indication is a position-related component load indication, which is determined based on the stored torque and the stored position. In this way, it is possible to determine a component load specification for a route traveled with the motor vehicle. It is possible to carry out the method with different drivers and / or different vehicles several times in succession in order to obtain a statistical evaluation of the component load information for a certain distance.

In this context, it has proved to be advantageous if the position-determining device has a receiver set up to receive satellite navigation signals. The receiver is preferably configured to receive satellite navigation signals from a global navigation satellite system, such as Global Positioning System (GPS), Global Navigation Satellite System (GLONASS), Galileo or Beidou.

A preferred embodiment of the method provides that the measured torque is monitored for load changes. Load changes of the torque on the stabilizer element represent a stress which may have an influence on the service life of the stabilizer element or on the service life of components connected to the stabilizer element, for example a coupling rod. In this respect, it becomes possible via the monitoring and possibly detection of the load changes to determine an overall damage of the stabilizer element and / or the component connected to the stabilizer element.

Preferably, the measured torque is stored when a load change of the torque has been detected. Since, above all, load changes are relevant for the determination of a total damage, in this way the number of measured values of the torque to be stored can be reduced.

Alternatively or additionally, it is preferable if the measured torque is classified into a torque class when a load change of the torque has been detected. A torque class represents a predetermined torque range with a lower limit and an upper limit. By classifying the measured torque into a torque class, the storing of the torque can be dispensed with. Rather, it is sufficient to increase a class counter of the torque class into which the measured torque has been classified.

In this context, it is advantageous if a partial damage is determined for each torque class. Each torque class can be assigned a constant torque. To determine the partial damage for each torque class, the number of determined load changes per torque class can be divided by the maximum sustainable number of load cycles at the constant torque in accordance with a Wöhler characteristic characteristic of the component, such as the stabilizer element or coupling rod.

Particularly preferred is an embodiment of the method in which a warning is generated when a sum of multiple partial damage exceeds a predetermined threshold. The predetermined threshold value is preferably chosen such that it is lower than a damage value at which a failure, in particular a fracture, of the component is to be feared. This makes it possible to warn the user of the motor vehicle of the likely failure of the component, so that an exchange of the component can take place before it comes to a failure of the component.

An advantageous embodiment provides that a further measured variable is measured with a further sensor, wherein the component load indication is determined on the basis of the measured torque and on the basis of the further measured variable. The further sensor may for example be a level sensor, via which the ride height of a body of the motor vehicle, in particular the distance of the body from a wheel of the motor vehicle, is measured.

According to an advantageous embodiment, the component load indication is determined in an evaluation device, which is arranged remotely from the motor vehicle. For this purpose, the measured torque and / or the determined torque class and / or the position of the motor vehicle can in particular be transmitted wirelessly to the evaluation device. In this case, a separate communication connection can be provided from the at least one roll stabilizer sensor and the position determination device to the evaluation device. Alternatively, the motor vehicle may have a navigation system via which the measured torque and / or the determined torque class and / or the position of the motor vehicle is transmitted to the evaluation device become. Alternatively it can be provided that the component load indication is determined in an evaluation device in the motor vehicle.

Another object of the invention is a motor vehicle with at least one roll stabilizer having a roll stabilizer sensor, wherein by means of the roll stabilizer sensor, a torque is directly or indirectly measurable, which claims a stabilizer element of the roll stabilizer to torsion, and with an evaluation set up is to determine a component load specification based on the measured torque.

In the motor vehicle, the same advantages can be achieved, as have already been described in connection with the inventive method for monitoring the load of a chassis component when driving with a motor vehicle.

In the motor vehicle, alternatively or additionally, the advantageous features or embodiments may be used, which have been described in connection with the method according to the invention for monitoring the load of a chassis component when driving with a motor vehicle.

• 1 ein Ausführungsbeispiel eines erfindungsgemäßen Kraftfahrzeugs in einer schematischen Darstellung,
• 2 ein Ausführungsbeispiel eines erfindungsgemäßen Verfahrens in einem Flussdiagramm und
• 3 ein Wöhler-Diagramm zur Veranschaulichung der Abläufe Verfahren gemäß einem Ausführungsbeispiel der Erfindung.

Further details and advantages of the invention will be explained below with reference to the embodiment shown in the drawings. Hereby shows:

• 1 An embodiment of a motor vehicle according to the invention in a schematic representation,
• 2 an embodiment of a method according to the invention in a flowchart and
• 3 a Wöhler diagram illustrating the procedures of a method according to an embodiment of the invention.

In the 1 is a motor vehicle 1 according to an embodiment of the invention, which is for carrying out a method for monitoring the load of a chassis component when driving with a motor vehicle 1 suitable is. The car 1 has a arranged on a front axle, first roll stabilizer 2 and a second roll stabilizer disposed on a rear axle 2 ' on. the roll stabilizers 2 . 2 ' are designed as active, in particular electromechanical, roll stabilizers. The first and the second roll stabilizer 2 . 2 ' each has an actuator, in particular an electric motor, which can generate a torsional or torsional moment. Both roll stabilizers 2 . 2 ' each have a roll stabilizer sensor for measuring a torque that claims a stabilizer element to torsion. In addition, in both roll stabilizers 2 . 2 ' further roll stabilizer sensors are provided, via which a rotation angle between two elements of the roll stabilizer 2 . 2 ' , a speed of the actuator of the roll stabilizer 2 . 2 ' and the temperature can be measured.

The car 1 Also includes several, in particular four, level sensors 3 . 3. ' . 3 ' , 3 "', which each measure the ride height of the body on a wheel of the motor vehicle, in particular the distance between the body and the respective wheel. The wheels may be both driven and non-driven wheels Wheels be provided more wheel bearing sensors.

Another component of the motor vehicle 1 is a position determination device 4 , about which the position of the motor vehicle 1 can be determined. The position determination device 4 has a receiver configured to receive satellite navigation signals. The receiver is preferably set up to receive satellite navigation signals from a global navigation satellite system, such as the GPS, GLONASS, Galileo or Beidou.

Furthermore, the motor vehicle includes 1 an evaluation device 5 , which is set up to determine a component load specification at least on the basis of the measured torque. The component load indication comprises an indication of the load of the stabilizer element of the roll stabilizer, for example an average applied torque, a minimum torque, a maximum torque, a torque range, a time profile of the torque or a total damage of the stabilizer element. Furthermore, the component load indication may include an indication of a load on a component connected to the roll stabilizer, in particular a coupling rod. The component load specification may be an average tensile force, a minimum tensile force, a maximum tensile force, a tensile force span, a time course of the tensile force or a total damage of the component connected to the roll stabilizer, in particular the coupling rod.

Alternatively, the component load indication may be a positional component load indication determined from the stored torque and stored position. This position-related component load specification can be present as a data packet which, in addition to the component load specification, additionally contains a position to which the component load specification refers. The position-related component load indication can be stored in a vehicle-mounted memory 10 be stored or transmitted via a particular wireless communication connection to a vehicle external memory. The position-related component load data determined in this way can be used to enable a statistical evaluation of the component load specifications for a specific distance.

Based on the illustration in 2 is intended below to an embodiment of a method for monitoring the load of a chassis component when driving with a motor vehicle 1 be taken as the example of 1 has been described. The chassis component can be, for example, a stabilizer element of a roll stabilizer or a coupling rod.

The roll stabilizer sensors of the two roll stabilizers 2 . 2 ' measure in one measuring step 100 continuously. It monitors whether a load change on one of the roll stabilizers 2 . 2 ' is present, ie whether the sign measured torque has changed between a first measured value and a second measured value. When in measuring step 100 a load change is detected is in a detection step 101 the measured torque is stored. In addition, a classification of the measured torque takes place. Here the measured torque becomes a torque class M ₁ . M ₂ . M ₃ . M ₄ classified, cf. 3 , These torque classes are each assigned a constant torque. In the classification, the measured torque is assigned to that torque class whose constant torque comes closest to the measured torque. In this respect, every torque class represents M ₁ . M ₂ . M ₃ . M ₄ By classifying the measured torque into a torque class, it is possible to dispense with storing the measured torque and, instead, to capture only the number of measurement points per torque class. For this purpose, a class counter is provided for each torque class, which is then increased if a measured torque is classified into the respective torque class during a load change. The detection step described above 101 can in the evaluation device 5 of the motor vehicle 1 be performed.

In the embodiment, in a transmission step 102 the detected information, in particular wireless, to a navigation system of the motor vehicle 1 transmitted.

In a subsequent submission step 103 become the captured information from the motor vehicle 1 , in particular of the navigation system of the motor vehicle 1 transmitted to a remote from the motor vehicle evaluation. This transmission preferably takes place wirelessly, in particular via a radio link.

In the evaluation step 104 the evaluation of the transmitted information takes place in the evaluation unit. This is for each torque class M ₁ . M ₂ . M ₃ . M ₄ a partial damage is determined, wherein the number of determined load changes per torque class M ₁ . M ₂ . M ₃ . M ₄ is determined by the maximum sustainable number of load changes at the respective constant torque of the torque class. For this purpose, a Wöhler characteristic characteristic of the component is used, which is stored in the evaluation unit. The Wöhler characteristic 200 are dependent on the number of load changes N the torque M at which a failure of the component is likely. An exemplary Wöhler diagram with a Wöhler characteristic 200 is in the 3 shown.

In the evaluation step 104 the sum of the partial damages is formed and compared with a predetermined threshold value. The predetermined threshold value is preferably chosen such that it is lower than the damage value at which a failure, in particular a break, of the component is to be feared. If the sum of the partial damages exceeds the predetermined threshold, a warning is generated indicating that a component failure is likely. The warning is preferred to the motor vehicle 1 transmitted and the driver of the motor vehicle 1 displayed.

LIST OF REFERENCE NUMBERS

1

motor vehicle

2, 2 '

roll stabilizer

3, 3 ', 3 ", 3'"

Level sensor

4

Location facility

5

calculator

10

Storage

100

measuring step

101

detecting step

102

transmission step

103

transmission step

104

evaluation step

200

SN curve

M

torque

M ₁

torque class

M ₂

torque class

M ₃

torque class

M ₄

torque class

N

Number of load cycles

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 9108640 B2 [0002]

Claims (10)

Method for monitoring the load of a chassis component when driving with a motor vehicle (1) having at least one roll stabilizer (2, 2 ') with a roll stabilizer sensor, wherein the roll stabilizer sensor, a torque is measured directly or indirectly, which a stabilizer element of the roll stabilizer claimed to torsion, and based on the measured torque, a component load indication is determined. Method according to Claim 1 , characterized in that the component load indication comprises an indication of the load of the stabilizer element of the roll stabilizer (2, 2 '). Method according to one of the preceding claims, characterized in that the component load indication comprises an indication for a load of a component connected to the roll stabilizer (2, 2 '), in particular a coupling rod. Method according to one of the preceding claims, characterized in that the motor vehicle has a position determining device (4), wherein the position determining means (4) the position of the motor vehicle (1) during the measurement of the torque is determined and the determined component load indication a position-related component load indication is determined based on the stored torque and the stored position. Method according to one of the preceding claims, characterized in that the measured torque is monitored for load changes. Method according to Claim 5 , characterized in that the measured torque is stored when a load change of the torque has been detected. Method according to one of Claims 5 or 6 , characterized in that the measured torque is classified into a torque class (M ₁ , M ₂ , M ₃ , M ₄ ) when a load change of the torque has been detected. Method according to Claim 7 , characterized in that a partial damage is determined for each torque class (M ₁ , M ₂ , M ₃ , M ₄ ). Method according to Claim 8 , characterized in that a warning is generated when a sum of multiple partial damage exceeds a predetermined threshold. Motor vehicle with at least one roll stabilizer (2, 2 ') having a roll stabilizer sensor, wherein by means of the roll stabilizer sensor, a torque is directly or indirectly measurable, which claims a stabilizer element of the roll stabilizer (2, 2') to torsion, and with an evaluation device which is set up to determine a component load specification based on the measured torque.

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